Scroll to the bottom section of the board and you'll sometimes see routes labeled "Building history," shown dimmer than the rest. That's not a bug or a placeholder — it's an honest state we show on purpose, for a specific reason.
A route needs at least 7 distinct days of accumulated price history before we'll classify it as a deal — or rule it out as "priced, not a deal." An average built on 2 or 3 days of data isn't statistically meaningful yet; calling something a 25% discount off a 2-day average is a much weaker claim than the same math off a real 30-day trailing average. Below that 7-day threshold, we'd rather say "not enough data yet" than dress up a shaky number as a confident one.
An earlier version of the board treated every card the same regardless of how much history backed it — a genuinely misleading presentation, since "no real signal yet" and "priced and not currently a deal" look identical to a reader skimming the page. The dimmed treatment (technically a .grid-dimmed style) exists specifically so a route without enough history reads as visually different at a glance, not just in the fine print.
A missing day — a fetch that didn't return a result — is simply skipped, never backfilled with a guessed or repeated price. A synthetic number would quietly corrupt the exact average every other calculation on the site depends on. Full details on that average in how we rank deals.